title: Synthesis of 3-aryl-2-arylamidobenzofurans based on the Curtius rearrangement.
abstract: The synthesis of novel 3-aryl-2-arylamidobenzofurans has been accomplished via a Curtius rearrangement strategy in four steps from benzofuran-2-carboxylic acids. The requisite Suzuki-Miyaura cross-coupling, with benzyl 3-bromobenzofuran-2-ylcarbamate or 2-arylamido-3-bromobenzofurans, revealed an unusual reductive debromination process due to the presence of the free NH group. This dehalogenation can be suppressed by N-alkylation. DMAP is an efficient reagent for the one-pot conversion of benzyl benzofuran-2-ylcarbamates into the corresponding benzofuran-2-arylamides through aroylation, thus acting both as an acyl transfer reagent and a deprotecting agent of the Cbz group. A mechanism is postulated.
authors.affiliation: CNRS UMR 176, 26 rue d'Ulm, 75248 Paris, France.
authors.forename: Amandine
authors.initials: A
authors.lastname: Carrër
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Florent
authors.forename: Emilie
authors.initials: E
authors.lastname: Auvrouin
authors.forename: Patricia
authors.initials: P
authors.lastname: Rousselle
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Bertounesque
mesh_terms: D015761:4-Aminopyridine / Q000031:analogs & derivatives / Q000737:chemistry; D000478:Alkylation; D000577:Amides / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D001572:Benzofurans / Q000138:chemical synthesis*; D001688:Biological Products / Q000138:chemical synthesis*; D001897:Boronic Acids / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry; D002384:Catalysis; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D013237:Stereoisomerism
chemical_list: D000577:Amides; D000588:Amines; D001572:Benzofurans; D001688:Biological Products; D001897:Boronic Acids; D002264:Carboxylic Acids; D015761:4-Aminopyridine; C003885:4-dimethylaminopyridine